Epoxy fix for old wooden boat
colw...@tc.umn.edu
epoxy for a "permanent" hull, could one buy one of these beautiful old
wooden boats and do the same thing, inside and out, to seal up the hull
and protect it from moisture and rot?
KPB314159
epoxe. Buy I have seen many failed attempts to slather epoxe over traditional
craft. I think the issue here is that if you allow any moisture changes to
get to the wood it WILL expand and contract and destroy whatever it has to in
the process. I think it's all or nothing: either totally encapsulate the wood
in plastic inside and out or avoid it. You can get WEST's pamphlet on this
subject but I would reccomend treating it as only one input of many. Case in
point: they show a fix for floor timbers that makes no mention of leaving
limber holes.
Ken Bowen
Gregg Germain
: Since one can supposedly build a boat of plywood and encapsulate it with
: epoxy for a "permanent" hull, could one buy one of these beautiful old
: wooden boats and do the same thing, inside and out, to seal up the hull
: and protect it from moisture and rot?
The only way to destroy a traditionally built boat faster than epoxy
encapsulation is to drive it onto the rocks at max speed.
You will not successfully encapsulate the boat entirely, and even if
you did, the encapsulation will be penetrated at some point and when
that happens, moisture gets to the wood and destroys it.
Pass up the old wooden boat if you are NOT interested in
rebuilding/restoring it using it's original techniques.
--- Gregg
Replicas of 15th-19th century nautical navigational instruments:
http://people.ne.mediaone.net/saville/backstaffhome.html
Restoration of my 81 year old Herresoff S-Boat sailboat:
http://people.ne.mediaone.net/saville/SBOATrestore.htm
Steambending FAQ with photos:
http://people.ne.mediaone.net/saville/Steambend.htm
"Eschew surplusage."
gr...@head-cfa.harvard.edu
Smithsonian Center for Astrophysics Mark Twain
Phone: (617) 496-7237
Gary Zwissler
monocoque structures and are very rigid, in fact as rigid, if no more than
most fiberglass boats. The stable structure is ideal for encapsulation
using epoxy and glass. Traditional construction using plank on frame is not
as rigid, and in fact moves quite readily compared to a plywood hull. For
this reason attempts to encapsulate will fail as the epoxy glass covering
will ultimately crack, leading to saturation of the wood core, and
ultimately rot. Any good book on epoxy encapsulation, even the ones
distributed by manufacturers will address this issue.
je...@messinginboats.com <colw...@tc.umn.edu> wrote in message
news:3B3893E2...@tc.umn.edu...
P.C.
Gary Zwissler skrev i meddelelsen ...
>For
>this reason attempts to encapsulate will fail as the epoxy glass covering
>will ultimately crack, leading to saturation of the wood core, and
>ultimately rot. Any good book on epoxy encapsulation, even the ones
>distributed by manufacturers will address this issue.
Now this I don't fully understand. Rot need oxygen that's my experience, and I
often seen old boat hulls where the freeboard is bad, but where the underwater
part of the hull is in fairly good condision.
"Rot" don't just occour as soon as wood get wet, ---- most wood's have a good
"build-in" resistance against "rot" and if soaked thru myselia simply can't
grow.
Many museums have develobed different methods in order of presaving aincient
wrecks, and you don't have to study the issue for long, to find out that as soon
as oxygen is kept away from the wood, rot don't occour ,-------- like when wood
is left underwater, rot simply can't survive. ------ Beside "rot" is not a
simple process, but is a process where several species of "rot" live from one
another, so if you "break" one part of that "chain", you have a chance fighting
"rot".
Often I seen wooden hulls where the outside underwater hull was good, but all
depending what kind of wood ,there could be different kinds of "rot" either
between the ribs , or like with Oak underneath the frames.
Sure ply can rot as the kind of wood it's made of can rot, and fact is that
"rot" is _everywhere_ around , just waiting for the right condisions to grow ;
often this mean that there need to be a "lower" specie to feed from. But these
day's the trend in wooden boatbuilding say Ply, ply and ply again, and as
amatures rule it can't be thin enough and when that become a problem, you just
plaster it over with the _cheapest_ stuff you can get ; that's not as bad as you
would think while then it don't matter if you used screws in endwood ,or didn't
maneage to make an edge frame holding side panels and aft mirror together.
No ; Rot is _not_ the worse problem, in wooden boatbuilding acturly from _my_
point of view, the worse problem is when well proven methods is sacrifised by
the "need" of simple construction methods .
Ply is a nice material, and many realy good plywood boats and kits have been
manufactored, ------- just like many real wooden boats have been and have proven
their abilities. But if you build a Riva form the cheapest douglas ply you can
find you get just that ; ---------- think it would last 60 years ?
It proberly would not, at the builder would not seal the plank ends or work each
square inch of the planking, each piece would proberly try to twist each
fastning and then you can ask yourself what will last best , bronce screws and
copper rivest ,or a seam of twisted thin copper wire.
Another source of rot, is lack of maintainment. How much time are spend
maintaining a hull build in "expensive" materials compared with a hull same size
in the cheapest materials found. ------------ Guess yo know that when I write
"expensive" I personally mean materials chosen not by cost but from a choice of
what will be best in terms of strength and workability, as it's a fact that the
expensive stuff is acturly easyest to work with. while suggesting rough cheap
qualities often leave an amature with panels with rough edges ; in this groupe I
never read anyone saying that you "pay" for the cheap cost, by more trouble
working the materials, ------- still this is a fact that obviously shuld be
interesting to know for an amature, and I never found the reson why noone tell.
Anyway, -------- back to issue ,no polyester _or_ epoxies can or shuld
compensate a cheap plywood, or a plywood made for a totally different porpus.
Ok ; soon there will only be the designs awaible from back 60 years ago
origianally build from planks and timbers or the P.M. plywood boats from the
50's so maby it's not that big a problem anyway.
---------- Still there ain't many left of either of them.
Have a nice day.
P.C.
http://w1.1396.telia.com/~u139600113/
Tom & Rita Hunter
For background I have a 31 foot cold molded Quoddy Pilot that is currently
next to Gregg Germain's boat.
My boat was built in 1971 and is made of wood, completely encased in
fiberglass and ballasted internally with concrete. I have opened up the
hull in one place where the glass was cracked and water was seeping out and
not found rot. I believe there was no rot because the water coming in was
salt not fresh which brings me to my first point you need to keep fresh
water out of the wood salt water is not so much of an issue.
That said the point is to keep the boat floating and if enough salt water
gets in you may sink.
The reason that you are likely to fail is that keeping the fresh water out
is going to be very difficult. you would have to empty the hull completely,
take off all the paint and epoxy and glass the entire hull with enough
material to stiffen the hull and resist cracking. I think the concrete that
they filled my boat with may also be part of the secret, because the bottom
of the frames are under 3' of the stuff they don't work back and forth much
and they don't get wet from rain or condensation.
The assured destruction of the boat that Gregg and others are talking about
happens when you take a wooden boat and epoxy or fiberglass the outside of
the hull but leave the inside unfinished. I have seen boats that had this
done in the 1960's that were still sailing but the frames and ribs had
decayed away to nothing in places. The boat gets some stiffness from the
glass hull but I still think trouble will come one day.
For practical purposes I don't think you can do this and save a boat unless
you take the drastic steps I outlined above. If you are going to do that
much work why not just fix the boat? And few boats are designed in a way
that makes the concrete ballast practical, mine is a pinky hull and 1850's
design that had internal ballast when it was conceived and some of them got
concrete right away.
You can do this if you want to get some number of years out of a boat that
you know you are wrecking. I would not choose that course of action but
plenty of people do.
Good luck,
Tom Hunter
Patrick R. Weaver
Don't do it. You're mixing very different types of construction and you're
likely to get the worst of both. Either method if done well can be
satisfying but if you think you can avoid normal maintenance by epoxy
encapsulating a boat, think again. Epoxy isn't UV resistant and requires
painting or varnishing. That means the hull maintenance is about the same.
All you are doing is adding weight without adding anything to the structure
of the boat. Traditionally built boats are strong enough on their own. True
plywood/epoxy boats aren't really wooden boats. They are a composite
structure much like a fiberglass boat is. Epoxy has it's uses even in
traditional boat restoration but encapsulating isn't one of them.
Jon Etheredge
On Wed, 27 Jun 2001, Tom & Rita Hunter wrote:
> Some thoughts on your question
> For background I have a 31 foot cold molded Quoddy Pilot that is currently
> next to Gregg Germain's boat.
>
> My boat was built in 1971 and is made of wood, completely encased in
> fiberglass and ballasted internally with concrete. I have opened up the
> hull in one place where the glass was cracked and water was seeping out and
> not found rot. I believe there was no rot because the water coming in was
> salt not fresh which brings me to my first point you need to keep fresh
> water out of the wood salt water is not so much of an issue.
>
This is one of the "Quoddy Pilot" boats built by Carl Lane's Penobscot
Boatworks (aka Penbo) in Rockport, Maine? I thought those were all
strip-planked with White Cedar and then sheathed with polyester resin and
'glass. I didn't realize any of them were cold-molded although there was
a carvel planked one built by The Rockport Apprenticeshop.
I used to live in Rockport and always heard that the Penbo boats are nice
boats but...
I also heard that water intrusion could be problematic on them. I believe
that Taylor Allen at Rockport Marine has had experience with replacing
planking due to water migrating into the hulls through damage in the
exterior hull sheathing on the Pinky and Quoddy Pilot boats. I think that
the planking doesn't rot because of the lack of oxygen in between the
layers of fiberglass. But I think that there are still concerns about the
strength of the laminate when it is water-logged rather than dry since it
was originally designed to be dry.
Jon
Gary Zwissler
It would seem you have an opinion about all of this :) Can't disagree with
what you've said. But I never said that water under the waterline was the
source of rot. In my experience rot most often occurs from fresh water
entering from above, either in the form of condensation, rain, or boat
washing. Movement between the hull members, decks, and cabins of
traditional construction is all greater than on plywood monocoque
construction. I have personal experience with this kind of mistake. For
that reason I believe that one should be extremely careful when mixing
construction methods. If its traditional construction, keep it that way,
and vice-versa.
Gary
P.C. <per.c...@gentofte.mail.telia.com> wrote in message
news:9hciq6$e9r$1...@news.inet.tele.dk...
P.C.
Gary Zwissler skrev i meddelelsen ...
>Per,
>
>It would seem you have an opinion about all of this :) Can't disagree with
>what you've said. But I never said that water under the waterline was the
>source of rot. In my experience rot most often occurs from fresh water
>entering from above, either in the form of condensation, rain, or boat
>washing. Movement between the hull members, decks, and cabins of
>traditional construction is all greater than on plywood monocoque
>construction
You are quite right, ----- Rot also have some strong enemies ; ventilation
,simple care, a watertight deck _and_ some of the anti rot means that is water
based .
I guess you know that particular smell that make the alarm bells ring when you
enter a cabin that have been locked tight for a long time , ------- and you
proberly also are right that fresh water _are_ worse than salt ; I belive so to,
even I newer have been able to prove it, and I often talked against it. But
that's becaurse ,when you state that fresh water are bad, then people think salt
water is good while some rot species wouldn't be without the spice.
Varnish and care allways been the best treatment for plywood ;))
Tom & Rita Hunter
> This is one of the "Quoddy Pilot" boats built by Carl Lane's Penobscot
> Boatworks (aka Penbo) in Rockport, Maine?
Yes
> I thought those were all
> strip-planked with White Cedar and then sheathed with polyester resin and
> 'glass. I didn't realize any of them were cold-molded although there was
> a carvel planked one built by The Rockport Apprenticeshop.
After opening mine up I am pretty sure that it was not poly resin but epoxy. It
was strip planked but there were none of the staples that are usually used to
hold poly resin to wood and the binding material adhered to the wood the same way
epoxy on some of my other projects does. Still its possible that I am wrong
about that.
I guess part of the question is how do you define cold molded. Certainly the
boat was not built with thin layers of wood laminated together with epoxy the way
a current cold molded boat is built. Maybe the state of the art evolved over the
last 30 years or maybe its not really a cold molded boat at all and I need to
call it something else.
>
>
> I used to live in Rockport and always heard that the Penbo boats are nice
> boats but...
>
> I also heard that water intrusion could be problematic on them. I believe
> that Taylor Allen at Rockport Marine has had experience with replacing
> planking due to water migrating into the hulls through damage in the
> exterior hull sheathing on the Pinky and Quoddy Pilot boats. I think that
> the planking doesn't rot because of the lack of oxygen in between the
> layers of fiberglass. But I think that there are still concerns about the
> strength of the laminate when it is water-logged rather than dry since it
> was originally designed to be dry.
I had these concerns which is why I opened up part of the hull. On the section
that I opened up things looked fine. At the end of the season this year I plan
to open all the cracks and re-sheath after the hull dries out.
So far the places where I have found rot have all been places where there was
glass over wood on one side but not the other mainly in the cockpit which
supports Gregg's thesis that glass over wood is problematic.
If you have any more information on problems with/repairs to these boats I would
love to hear it forewarned is forearmed after all.
Tom Hunter
>
>
> Jon
Gregg Germain
: The assured destruction of the boat that Gregg and others are talking about
: happens when you take a wooden boat and epoxy or fiberglass the outside of
: the hull but leave the inside unfinished.
I also assure destructionif one attempts to epoxy and/or glass
both the inside and outside of a traditionally built boat:
You can't get a good seal everywhere (think of the sheer clamp), and
anyways the encapsulation will be pierced at one point or another.
--- Gregg
Jon Etheredge
comments inline...
On Thu, 28 Jun 2001, Tom & Rita Hunter wrote:
> John
>
> > This is one of the "Quoddy Pilot" boats built by Carl Lane's Penobscot
> > Boatworks (aka Penbo) in Rockport, Maine?
>
> Yes
>
>
> > I thought those were all
> > strip-planked with White Cedar and then sheathed with polyester resin and
> > 'glass. I didn't realize any of them were cold-molded although there was
> > a carvel planked one built by The Rockport Apprenticeshop.
>
> After opening mine up I am pretty sure that it was not poly resin but epoxy. It
> was strip planked but there were none of the staples that are usually used to
> hold poly resin to wood and the binding material adhered to the wood the same way
> epoxy on some of my other projects does. Still its possible that I am wrong
> about that.
>
You may be right about the use of epoxy rather than polyester.
> I guess part of the question is how do you define cold molded. Certainly the
> boat was not built with thin layers of wood laminated together with epoxy the way
> a current cold molded boat is built. Maybe the state of the art evolved over the
> last 30 years or maybe its not really a cold molded boat at all and I need to
> call it something else.
Guess I was nit-picking here. Sorry about that.
To me, cold molding implies multiple layers of "veneer" (may or may not be
thin, depending on the size of boat). This may be too limited a
definition though.
> >
> > I used to live in Rockport and always heard that the Penbo boats are nice
> > boats but...
> >
> > I also heard that water intrusion could be problematic on them. I believe
> > that Taylor Allen at Rockport Marine has had experience with replacing
> > planking due to water migrating into the hulls through damage in the
> > exterior hull sheathing on the Pinky and Quoddy Pilot boats. I think that
> > the planking doesn't rot because of the lack of oxygen in between the
> > layers of fiberglass. But I think that there are still concerns about the
> > strength of the laminate when it is water-logged rather than dry since it
> > was originally designed to be dry.
>
> I had these concerns which is why I opened up part of the hull. On the section
> that I opened up things looked fine. At the end of the season this year I plan
> to open all the cracks and re-sheath after the hull dries out.
>
> So far the places where I have found rot have all been places where there was
> glass over wood on one side but not the other mainly in the cockpit which
> supports Gregg's thesis that glass over wood is problematic.
>
> If you have any more information on problems with/repairs to these boats I would
> love to hear it forewarned is forearmed after all.
>
I can't provide any more info myself. But Rockport Marine might be able
to help. They used to advertise in WoodenBoat magazine.
Jon
KPB314159
the famous cruising boat "Curlew" In which they took a sound but aged
traditional boat, dried it out, diagonally veneered the outside and I believe
glassed it but left the inside au-natural. Anyone know how this approach has
stood up over time?
Ken Bowen
Ryan Young
technique.
The good news: if properly exectuted, on the proper boat, yes, it holds up
nicely. Boats treated this way in the Caribbean 15 years ago, and well
maintained since then are still tight and sound.
The bad news is that it's about as much work as building a new boat, and
it's probably best suited to a relatively light, but well engineered boat
that is thoroughly dry.
Basically, a new cold molded epoxy saturated hull, fully capable of taking
all structural loads, is mechanically fastened and built around the old
hull.
And it can be argued that a boat worth saving in this way (say, a Herresoff
S-boat, poke, hint, nod) is worth restoring in the traditional manner.
A cheaper way to save a tired, but worthy wooden boat, is to cover it with a
similarly stout fiberglass hull. Allen Vaitses specialized in this, and his
"Covering Wooden Boats With Fiberglass" tells you all you need to know to do
this successfully. Again, a new boat is built, mechanically fastened to the
old one, using the existing hull as a mold. 4 layers of mat and woven
roving are the minimum. This creates a hull stiff enough to resist the
movement BIG pieces of wood want to create when they change their moisture
content. Anything less, and the wood will fail in shear as it moves, or the
glass will crack at the seams.
--
Ryan R Young
Oakland, CA
http://users.lmi.net/~ryoung
Gregg Germain
: And it can be argued that a boat worth saving in this way (say, a Herresoff
: S-boat, poke, hint, nod) is worth restoring in the traditional manner.
;^)